Microsoft has blamed an unspecified server problem for a 19-hour stretch during which paying users of Windows XP and Vista were accused by the company's "Windows Genuine Advantage" validation system of running pirated software.
Any Vista system fingered during the episode was stripped of some features, including the operating system's Aero graphical interface.
The incident began on Friday afternoon (24 August) , Microsoft said the problem had been fixed and was fixed the following morning..
"We are aware it is a server-side issue," said Phil Liu, a Microsoft program manager in the Windows Genuine Advantage (WGA) group. "[But] the cause is unknown at this current time."
"Customers who received an incorrect validation response can fix their system by revalidating on our site," added Alex Kochis, senior product manager of WGA in a blog posting. The site Kochis referred to is the Genuine Microsoft Software home page, which includes links to validation tests for Windows and Microsoft Office. "After successfully revalidating any affected system should be rebooted to ensure the genuine-only features are restored," Kochis continued.
The validation server snafu began sometime prior to 8 p.m. Eastern time on Friday, when users started posting messages on Microsoft's support forums including Vista Validation Issues, saying that their PCs had been tagged as running non-genuine Windows. Overnight, the number of users adding their accounts to the tale spiked significantly, as did the frustration index.